One type of sunroof assembly that has gained popularity and widespread use in recent years includes a manually operable sunroof panel which is mounted by hinges or latches on a frame that can be easily installed in the vehicle's roof either at the factory at the time the vehicle is manufactured, or at a later point in time as a retrofit to the vehicle.
The frames used in the sunroof assemblies of the type described above normally employ a primary frame section which overlies the upper surface of the roof and which includes a peripheral flange for supporting the sunroof panel. A weatherstrip mounted in a channel formed on the flange engages the panel and is intended to prevent the entry of moisture into the vehicle between the panel and the surrounding frame. In some cases, the weatherstrip is held in place on the flange by means of a suitable adhesive. In other designs, the weatherstrip mounting consists of an interlocking connection between the weatherstrip and the frame; a portion of the weatherstrip is held within specially configured ways defined by undercuts in the frame.
Neither of these prior art techniques of mounting the weatherstrip on the frame is totally effective in sealing the sunroof assembly against moisture penetration. Adhesives sometimes harden and crack or otherwise deteriorate, thus allowing entry of moisture. Mechancial interlocks require tolerances between the weatherstrip and the frame undercuts which create a path for the entry of moisture. The possibility of moisture entry in prior art sunroof assemblies is further increased due to the fact that the weatherstrip is not positively pressed against the frame to create a positive seal therebetween.
The prior art frames are rather complex in configuration for several reasons, including the need for providing undercuts therein which are used for mounting the weatherstrip, and the need for providing a cavity into which the edges of the interior headliner may be tucked in order to provide a finished appearance inside the vehicle. As a result of the relative complexity of frame geometry, particularly in cross-section, known prior art frames are normally manufactured by extrusion techniques. This manufacturing method is rather expensive on a piece part basis because a multiplicity of processing steps are required, including the step of making the initial extrusion, welding the ends of the extrusion together to form the frame, drilling the frame, hand finishing the extrusion, etc.
Consequently, there is a need in the art for a sunroof frame assembly which is particularly simple in design in order to reduce manufacturing costs, and which also provides an improved arrangement for mounting the weatherstrip in a manner which creates a positive, weather-tight seal. The present invention satisfies these objectives.